The present invention relates generally to non-fat and reduced-fat products which possess the organoleptic characteristics of full fat-containing products. More specifically, the invention relates to cream substitutes which comprise a core of carbohydrate surrounded by a shell of protein.
Singer et al., U.S. Pat. Nos. 4,734,287 and 4,961,953 disclose a proteinaceous, water-dispersible, macrocolloid comprising substantially non-aggregated particles of dairy whey protein and other proteins. The particles have mean diameter particle size distributions in a dried state ranging from about 0.1 microns to about 2.0 microns, with less than about 2 percent of the total number of particles exceeding 3.0 microns in diameter. Singer et al., U.S. Pat. No. 4,828,396 disclose fluid processing devices including means for generating toroidal flow in a fluid to be processed. The devices are capable of cooking under high shear rates and are useful for producing macrocolloids for use as fat substitutes.
Singer et al., U.S. Pat. No. 4,855,156 disclose non-fat and reduced fat whipped frozen desserts wherein part or all of the fat or oil ordinarily incorporated therein is replaced by a proteinaceous macrocolloid comprising denatured whey protein particles. Singer et al., U.S. Pat. No. 4,985,270 disclose non-fat and reduced fat whipped frozen dessert products wherein part or all of the fat or oil ordinarily incorporated therein are replaced by denatured whey protein particles or particles comprising a core of casein surrounded by a shell of denatured egg white protein. The patent further discloses the use of the composite egg white protein/casein particles as fat substitutes in sauces, dips, spreads, icing and cream pie fillings.
Carbohydrate-based fat substitutes have been proposed as low cost alternatives to the relatively expensive protein-based macrocolloid cream substitutes. Singer et al., U.S. Pat. Nos. 4,911,946 and 5,153,020, the disclosures of which are hereby incorporated by reference, disclose fat substitutes which comprise water-dispersible macrocolloidal particles composed of carbohydrate materials which particles have a substantially spheroidal shape and specific particle size distributions effective to impart the substantially smooth organoleptic character of an oil-in-water emulsion. These patents disclose carbohydrates that can attain a spheroidal or substantially round shape in the 0.1 to 5 micron diameter size range which are suitable for use as cream substitute ingredients. Starches which occur naturally as granules in this size range are suitable for use as cream substitutes and may be treated with cross linking agents to prevent excessive swelling beyond the desired size range. Carbohydrate materials which do not have a natural round shape can be treated by making a solution of the carbohydrate and converting the solution to a gel (typically in a field of high shear-force) so that a narrow distribution of gelled microparticles is formed.
Of interest to the present invention are the disclosures of Spiers et al. PCT Publication WO91/04674 and Spiers et al. PCT Publication WO 91/19424 which relate to alginate and pectin based fat substitutes. The WO 91/04674 publication discloses methods of forming alginate and pectin gels by forming an aqueous mixture of a water soluble or water dispersible alginate or pectin, a calcium ion sequestrant and a sparingly soluble calcium source at low temperature. The mixture is then heated to cause gelation thereof. The WO 91/19424 publication discloses the use of sequestered divalent metal ions such as calcium ions in the production of alginate and pectin microparticulate beads having a size range of from about 15-300 .mu.m for use as fat substitutes. Such fat substitutes are not completely satisfactory because of their relatively large particle sizes, however. Moreover, carbohydrate-based cream substitutes are generally inferior to protein-based cream substitutes because they lack the superior functionality exhibited by proteins. Accordingly, there remains a desire in the art for improved carbohydrate containing fat substitutes which are characterized by the functionality of protein-based cream substitutes and methods for their production.